Solar cell array connections using corner conductors

ABSTRACT

A solar cell array is comprised of at least one solar cell and a substrate for the solar cell. The solar cell has at least one cropped corner that defines a corner region, wherein the corner region includes at least one contact for making an electrical connection to the solar cell. The contact comprises a front contact on a front side of the solar cell and/or a back contact on a back side of the solar cell, wherein the contact extends into the corner region. The solar cell is attached to the substrate such that corner regions of adjacent solar cells are aligned, thereby exposing an area of the substrate where electrical connections between the solar cells are made using corner conductors. The electrical connections are up/down and/or left/right series connections that determine a flow of current through the cells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. Section 119(e) ofthe following co-pending and commonly-assigned applications:

U.S. Provisional Application Ser. No. 62/394,636, filed on Sep. 14,2016, by Eric Rehder, entitled “SOLAR CELL ARRAY CONNECTIONS,”attorneys' docket number 16-0878-US-PSP (G&C 147.211-US-P1);

U.S. Provisional Application Ser. No. 62/394,616, filed on Sep. 14,2016, by Eric Rehder, entitled “CORNER CONNECTORS FOR A SOLAR CELLARRAY,” attorneys' docket number 16-0435-US-PSP (G&C 147.212-US-P1);

U.S. Provisional Application Ser. No. 62/394,623, filed on Sep. 14,2016, by Eric Rehder, entitled “PREFABRICATED CONDUCTORS ON A SUBSTRATETO FACILITATE CORNER CONNECTIONS FOR A SOLAR CELL ARRAY,” attorneys'docket number 16-0436-US-PSP (G&C 147.213-US-P1);

U.S. Provisional Application Ser. No. 62/394,627, filed on Sep. 14,2016, by Eric Rehder, entitled “SELECT CURRENT PATHWAYS IN A SOLARARRAY,” attorneys' docket number 16-0437-US-PSP (G&C 147.214-US-P1);

U.S. Provisional Application Ser. No. 62/394,629, filed on Sep. 14,2016, by Eric Rehder, entitled “MULTILAYER CONDUCTORS IN A SOLAR ARRAY,”attorneys' docket number 16-0438-US-PSP (G&C 147.215-US-P1);

U.S. Provisional Application Ser. No. 62/394,632, filed on Sep. 14,2016, by Eric Rehder, entitled “REWORK AND REPAIR OF COMPONENTS IN ASOLAR ARRAY,” attorneys' docket number 16-0439-US-PSP (G&C147.216-US-P1);

U.S. Provisional Application Ser. No. 62/394,649, filed on Sep. 14,2016, by Eric Rehder, entitled “POWER ROUTING MODULE FOR A SOLAR ARRAY,”attorneys' docket number 16-0440-US-PSP (G&C 147.217-US-P1);

U.S. Provisional Application Ser. No. 62/394,666, filed on Sep. 14,2016, by Eric Rehder, entitled “POWER ROUTING MODULE WITH A SWITCHINGMATRIX FOR A SOLAR CELL ARRAY,” attorneys' docket number 16-0441-US-PSP(G&C 147.218-US-P1);

U.S. Provisional Application Ser. No. 62/394,667, filed on Sep. 14,2016, by Eric Rehder, entitled “NANO-METAL CONNECTIONS FOR A SOLAR CELLARRAY,” attorneys' docket number 16-0442-US-PSP (G&C 147.219-US-P1);

U.S. Provisional Application Ser. No. 62/394,371, filed on Sep. 14,2016, by Eric Rehder, entitled “BACK CONTACTS FOR A SOLAR CELL ARRAY,”attorneys' docket number 16-0443-US-PSP (G&C 147.220-US-P1);

U.S. Provisional Application Ser. No. 62/394,641, filed on Sep. 14,2016, by Eric Rehder, entitled “PRINTED CONDUCTORS IN A SOLAR CELLARRAY,” attorneys' docket number 16-0614-US-PSP (G&C 147.228-US-P1); and

U.S. Provisional Application Ser. No. 62/394,672, filed on Sep. 14,2016, by Eric Rehder, Philip Chiu, Tom Crocker and Daniel Law, entitled“SOLAR CELLS FOR A SOLAR CELL ARRAY,” attorneys' docket number16-2067-US-PSP (G&C 147.229-US-P1);

all of which applications are incorporated by reference herein.

This application claims the benefit under 35 U.S.C. Section 120 of thefollowing co-pending and commonly-assigned applications:

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, entitled “PREFABRICATED CONDUCTORS ON A SUBSTRATE TOFACILITATE CORNER CONNECTIONS FOR A SOLAR CELL ARRAY,” attorneys' docketnumber 16-0436-US-NP (G&C 147.213-US-U1);

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, entitled “REWORK AND REPAIR OF COMPONENTS IN A SOLARARRAY,” attorneys' docket number 16-0439-US-NP (G&C 147.216-US-U1);

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, entitled “POWER ROUTING MODULE FOR A SOLAR ARRAY,”attorneys' docket number 16-0440-US-NP (G&C 147.217-US-U1);

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, entitled “POWER ROUTING MODULE WITH A SWITCHING MATRIXFOR A SOLAR CELL ARRAY,” attorneys' docket number 16-0441-US-NP (G&C147.218-US-U1);

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, entitled “NANO-METAL CONNECTIONS FOR A SOLAR CELLARRAY,” attorneys' docket number 16-0442-US-NP (G&C 147.219-US-U1); and

U.S. Utility application Ser. No. ______, filed on same date herewith,by Eric Rehder, Philip Chiu, Tom Crocker, Daniel Law and Dale Waterman,entitled “SOLAR CELLS FOR A SOLAR CELL ARRAY,” attorneys' docket number16-2067-US-NP (G&C 147.229-US-U1);

all of which applications claim the benefit under 35 U.S.C. Section119(e) of the co-pending and commonly-assigned provisional applicationslisted above: 62/394,636; 62/394,616; 62/394,623; 62/239,627;62/394,629; 62/394,632; 62/394,649; 62/934,666; 62/394,667; 62/694,371;62/394,641; and 62/394,672; and

all of which applications are incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under Contract No.FA9453-09C-0373 awarded by the Air Force Research Laboratory (AFRL). Thegovernment has certain rights in this invention.

BACKGROUND INFORMATION 1. Field

The disclosure is related generally to solar cell panels and morespecifically to electrical connections made between solar cells in anarray using corner conductors.

2. Background

Generally, the fabrication process for solar cell arrays is highlymanual and customizable. This is especially true for solar cell arraysthat are spaceflight capable. There is a lack of automated means formanufacturing solar cell arrays, while preserving the ability forcustomization.

Typical spaceflight-capable solar cell panel assembly involves buildinglong strings of solar cells. These strings are variable in length andcan be very long, for example, up to and greater than 20 cells.Assembling such long, variable, and fragile materials is difficult,which has prevented automation of the assembly.

Existing solutions use solar cells assembled into CIC (cell,interconnect and coverglass) units. The CIC has metal foil interconnectsconnected to the front of the cell that extend in parallel from one sideof the CIC. The CICs are located close to each other and theinterconnects make connection to the bottom of an adjacent cell. Usingthese interconnects, the CICs are assembled into linear strings. Theselinear strings are built-up manually and then laid out to form a largesolar cell array comprised of many strings of variable length.

Additionally, a bypass diode is used to protect the cells from reversebias, when the cells become partially shadowed. The bypass diodegenerally connects the back contacts of two adjacent cells within thesolar cell array.

Some small solar cell arrays attach solar cells to printed circuit board(PCBs) materials with embedded wiring. While this has some of theadvantages sought for automated manufacturing, it is specific andlimited in its design. As a result, they are not widely used insatellites.

When used in a satellite, the solar cell array is typically packaged asa panel. The dimensions of the panel are dictated by the needs of thesatellite, including such constraints as needed power, as well as thesize and shape necessary to pack and store the satellite in a launchvehicle.

Furthermore, the deployment of the panel often requires that someportions of the panel are used for the mechanical fixtures and the solarcell array must avoid these locations. In practice, the panel isgenerally rectangular, but its dimensions and aspect ratio vary greatly.The layout of the CICs and strings to fill this space must be highlycustomized for maximum power generation, which results in a fabricationprocess that is highly manual.

What is needed, then, is a means for promoting automated manufacturingof solar arrays, while preserving the ability for customization of solarcell arrays.

SUMMARY

To overcome the limitations in the prior art described above, and toovercome other limitations that will become apparent upon reading andunderstanding the present specification, the present disclosuredescribes a solar cell array comprised of at least one solar cell and asubstrate for the solar cell. The solar cell has at least one croppedcorner that defines a corner region, wherein the corner region includesat least one contact for making an electrical connection to the solarcell. The contact comprises a front contact on a front side of the solarcell and/or a back contact on a back side of the solar cell, wherein thecontact extends into the corner region. The solar cell is attached tothe substrate such that corner regions of adjacent solar cells arealigned, thereby exposing an area of the substrate where electricalconnections between the solar cells are made. The electrical connectionsare up/down and/or left/right series connections that determine a flowof current through the cells.

DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIGS. 1 and 2 illustrate conventional structures for solar cell panels.

FIGS. 3A and 3B illustrate an improved structure for solar cell panels,according to one example.

FIGS. 4A and 4B illustrate an improved structure for solar cell panels,according to another example.

FIG. 5 illustrates an exemplary solar cell, according to one example.

FIG. 6 illustrates the back side of the exemplary solar cell of FIG. 5.

FIG. 7 illustrates cells arranged into a two-dimensional (2D) grid of asolar cell array, according to one example.

FIG. 8 illustrates the addition of bypass diodes to one of the areas ofthe substrate exposed by the corner regions, according to one example.

FIG. 9 illustrates an example where the bypass diodes are applied to theback side of the cell, with an interconnect or contact extending intothe corner region, according to one example.

FIG. 10 illustrates a front side view of the example of FIG. 9, wherethe bypass diodes are applied to the back side of the cell, with theinterconnect or contact extending into the corner region, according toone example.

FIG. 11 illustrates the cells of FIGS. 9 and 10 assembled into the 2Dgrid of the array, where the bypass diodes are applied to the back sideof the cells, with the interconnects or contacts extending into thecorner regions of the cells, according to one example.

FIG. 12 shows an up/down series connection, according to one example.

FIG. 13 shows a left/right series connection, according to one example.

FIG. 14 is a flowchart illustrating the steps of a fabrication method,according to one example.

FIG. 15 is a solar cell, solar cell panel, satellite and/or spacecraftresulting from the fabrication method of FIG. 14, according to oneexample.

FIG. 16 is an illustration of a solar panel in the form of a functionalblock diagram, according to one example.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings which form a part hereof, and in which is shown by way ofillustration a specific example in which the disclosure may bepracticed. It is to be understood that other examples may be utilizedand structural changes may be made without departing from the scope ofthe present disclosure.

A new approach to the design of solar cell arrays, such as those usedfor spaceflight power applications, is based on electrical connectionsamong the solar cells in the array.

This new approach rearranges the components of a solar cell and thearrangements of the solar cells in the array. Instead of having solarcells connected into long linear strings and then assembled onto asubstrate, the solar cells are attached individually to a substrate,such that corner regions of adjacent cells are aligned on the substrate,thereby exposing an area of the substrate. Electrical connectionsbetween cells are made by corner conductors formed on or in thesubstrate in these corner regions. Consequently, this approach presentsa solar cell array design based on individual cells.

Thus, a single laydown process and layout can be used in the fabricationof solar cell arrays. Current flow between solar cells will be assistedwith conductors embedded in the substrate. These electrical connectionsdefine the specific characteristics of the solar cell array, such as itsdimensions, stayout zones, and circuit terminations. This approachsimplifies manufacturing, enables automation, and lowers costs anddelivery times.

FIGS. 1 and 2 illustrate conventional devices and structures for solarcell panels 10, which include a substrate 12, a plurality of solar cells14 arranged in an array, and electrical connectors 16 between the solarcells 14. Half size cells 14 are shown in FIG. 1 and full size cells 14are shown in FIG. 2. Space solar cells 14 are derived from a roundGermanium (Ge) substrate starting material, which is later fabricatedinto semi-rectangular shapes to improve dense packing onto the solarcell panel 10. This wafer is often diced into one or two solar cells 14herein described as half size or full size solar cells 14. Theelectrical connectors 16 providing electrical connections between cells14 are made along the long parallel edge between cells 14. These seriesconnections (cell-to-cell) are completed off-substrate, as strings ofconnected cells 14 are built having lengths of any number of cells 14.The completed strings of cells 14 are then applied and attached to thesubstrate 12.

In FIG. 2, wiring 18 is attached at the end of a string of cells 14 toelectrically connect the string to other strings, or to terminate theresulting circuit and bring the current off of the array of cells 14.String-to-string and circuit termination connections are typically doneon the substrate 12, and typically using wiring 18. However, some smallsolar arrays use a PCB-type material with embedded conductors.

Adjacent strings of connected solar cells 14 can run parallel oranti-parallel. In addition, strings of connected solar cells 14 can bealigned or misaligned. There are many competing influences to the solarcell layout resulting in regions where cells are parallel oranti-parallel, aligned or misaligned.

FIGS. 3A and 3B illustrate improved devices and structures for a solarcell panel 10 a, according to one example, wherein FIG. 3B is anenlarged view of the details in the dashed circle in FIG. 3A. Thevarious components of the solar cell panel 10 a are shown and describedin greater detail in FIGS. 5-13.

The solar cell panel 10 a includes a substrate 12 having one or morecorner conductors 20 thereon. In one example, the substrate 12 is amulti-layer substrate 12 comprised of one or more Kapton® (polyimide)layers separating one or more patterned metal layers. The substrate 12may be mounted on a large rigid panel 10 a similar to conventionalassembles. Alternatively, substrate 12 can be mounted to a lighter moresparse frame or panel 10 a for mounting or deployment.

A plurality of solar cells 14 arranged in an array 22 are attached tothe substrate 12. In this example, the array 22 is comprised ofninety-six (96) cells 14 arranged in four (4) rows by twenty-four (24)columns, but it is recognized that any number of cells 14 may be used indifferent implementations.

The solar cells 14 have cropped corners 24 that define corner regions26, as indicated by the dashed circle. The solar cells 14 are attachedto the substrate 12, such that corner regions 26 of adjacent ones of thesolar cells 14 are aligned, thereby exposing an area 28 of the substrate12. The area 28 of the substrate 12 that is exposed includes one or moreof the corner conductors 20, and one or more electrical connectionsbetween the solar cells 14 and the corner conductors 20 are made in thecorner regions 26 resulting from the cropped corners 24 of the solarcells 14.

In this example, the corner conductors 20 are conductive paths attachedto, printed on, or integrated with the substrate 12, before and/or afterthe cells 14 are attached to the substrate 12, which facilitateconnections between adjacent solar cells 14. The connections between thecells 14 and the corner conductors 20 are made after the cells 14 havebeen attached to the substrate 12.

In one example, four adjacent cells 14 are aligned on the substrate 12,such that four cropped corners 24, one from each solar cell 14, arebrought together at the corner regions 26. The solar cells 14 are thenindividually attached to the substrate 12, wherein the solar cells 14are placed on top of the corner conductors 20 to make the electricalconnection between the solar cells 14 and the corner conductors 20.

The solar cells 14 may be applied to the substrate 12 as CIC (cell,interconnect and coverglass) units. Alternatively, a bare solar cell 14may be applied to the substrate 12, and the coverglass later applied tothe front of the solar cell 14 with a transparent adhesive. Thisassembly protects the solar cells 14 from damage from space radiationthat would limit performance.

FIGS. 4A and 4B illustrate an alternative structure for the solar cellpanel 10 a, according to one example, wherein FIG. 4B is an enlargedview of the details in the dashed circle in FIG. 4A. In this example,only a few corner conductors 20 are printed on or integrated with thesubstrate 12. Instead, most of the corner conductors 20 are containedwithin a power routing module (PRM) 30 that is attached to the substrate12.

FIG. 5 illustrates the front side of an exemplary solar cell 14 that maybe used in the improved solar cell panel 10 a of FIGS. 3A-3B and 4A-4B.The solar cell 14, which is a CIC unit, is a half-size solar cell 14.(Full-size solar cells 14 could also be used.)

The solar cell 14 is fabricated having at least one cropped corner 24that defines a corner region 26, as indicated by the dashed circle, suchthat the corner region 26 resulting from the cropped corner 24 includesat least one contact 32, 34 for making an electrical connection to thesolar cell 14. In the example of FIG. 5, the solar cell 14 has twocropped corners 24, each of which has both a front contact 32 on thefront side of the solar cell 14 and a back contact 34 on a back side ofthe solar cell 14, where the contacts 32 and 34 extend into the cornerregion 26. (Full-size cells would have four cropped corners, each ofwhich would have a front contact and a back contact.)

The cropped corners 24 increase utilization of the round wafer startingmaterials for the solar cells 14. In conventional panels, these croppedcorners 24 result in unused space on the panel 10 after the solar cells14 are attached to the substrate 12. The new approach described in thisdisclosure, however, utilizes this unused space. Specifically, metalfoil interconnects, comprising the corner conductors 20, front contacts32 and back contacts 34, are moved to the corner regions 26. Incontrast, existing CICs have interconnects attached to the solar cell 14front side, and connect to the back side (where connections occur)during stringing.

The current generated by the solar cell 14 is collected on the frontside of the solar cell 14 by a grid 36 of thin metal fingers 38 andwider metal bus bars 40 that are connected to both of the front contacts32. There is a balance between the addition of metal in grid 36, whichreduces the light entering the solar cell 14 and its output power, andthe reduced resistance of having more metal. The bus bar 40 is a lowresistance conductor that carries high currents and also providesredundancy should a front contact 32 become disconnected. Optimizationgenerally desires a short bus bar 40 running directly between the frontcontacts 32. Having the front contact 32 in the cropped corner 24results in moving the bus bar 40 away from the perimeter of the solarcell 14. This is achieved while simultaneously minimizing the bus bar 40length and light obscuration. Additionally, the fingers 38 are nowshorter. This reduces parasitic resistances in the grid 36, because thelength of the fingers 38 is shorter and the total current carried isless. This produces a design preference where the front contacts 32 andconnecting bus bar 40 is moved to provide shorter narrow fingers 38.

FIG. 6 illustrates the back side of the exemplary solar cell 14 of FIG.5. The back side of the solar cell 14 is covered by a full area metalback layer 42 that is connected to both of the back contacts 34.

FIG. 7 illustrates solar cells 14 arranged into a two-dimensional (2D)grid for the solar cell array 22, according to one example. The array 22comprises a plurality of solar cells 14 attached to a substrate 12, suchthat corner regions 26 of adjacent ones of the solar cells 14 arealigned, thereby exposing an area 28 of the substrate 12. Electricalconnections (not shown) between the solar cells 14 are made in theexposed area 28 of the substrate 12 using the front contacts 32 and backcontacts 34 of the solar cells 14 and corner conductors 20 (not shown)formed on or in the exposed area 28 of the substrate 12.

During assembly, the solar cells 14 are individually attached to thesubstrate 12. This assembly can be done directly on a support surface,i.e., the substrate 12, which can be either rigid or flexible.Alternatively, the solar cells 14 could be assembled into the 2D grid ofthe array 22 on a temporary support surface and then transferred to afinal support surface, i.e., the substrate 12.

FIG. 8 illustrates an example of the array 22 where one or more bypassdiodes 44 are added to the exposed area 28 of the substrate 12 in thecorner regions 26, for use in one or more of the electrical connections.The bypass diodes 44 protect the solar cells 14 when the solar cells 14become unable to generate current, which could be due to being partiallyshadowed, which drives the solar cells 14 into reverse bias. In oneexample, the bypass diodes 44 are attached to the substrate 12 in thecorner regions 26 independent of the solar cells 14.

FIG. 9 illustrates an example where the bypass diode 44 is applied tothe back side of the solar cell 14, with an interconnect or contact 46for the bypass diode 44 extending into the corner region 26 between thefront and back contacts 32, 34.

FIG. 10 illustrates a front side view of the example of FIG. 9, with theinterconnect or contact 46 for the bypass diode 44 (not shown) extendinginto the corner region 26 between the front and back contacts 32, 34.

FIG. 11 illustrates the solar cells 14 of FIGS. 9 and 10 arranged intothe 2D grid of the array 22 and applied to the substrate 12, where thebypass diodes 44 (not shown) are applied to the back side of the solarcells 14, with the interconnects or contacts 46 for the bypass diodes 44extending into the corner regions 26 of the solar cells 14.

One advantage of this approach is that the layouts illustrated in FIGS.7, 8 and 11 are generalized layouts. Specifically, these layouts can berepeated across any panel dimensions desired by a customer. This greatlysimplifies assembly, rework, test, and inspection processes.

Following solar cell 14 and diode 44 placement, there is another stepwhere customization is accomplished. The front contacts 32 and backcontacts 34 in the corner regions 26 of the solar cells 14 must beconnected. This can be done in many combinations in order to routecurrent through a desired path.

After attaching solar cells 14 to the substrate 12, connections are madebetween the solar cells 14 and the corner conductors 20. Front and backcontacts 32, 34 of the solar cells 14 are present in each corner region26 for attachment to the corner conductors 20. Interconnects for thefront and back contacts 32, 34 of each of the solar cells 14 are welded,soldered, or otherwise bonded onto the corner conductors 20 to provide aconductive path 20, 32, 34 for routing current out of the solar cells14.

Using the corner conductors 20, any customization can be made in theelectrical connections. Adjacent solar cells 14 can be electricallyconnected to flow current in up/down or left/right directions as desiredby the specific design. Current flow can also be routed around stay-outzones as needed. The length or width of the solar cell array 22 can beset as desired. Also, the width can vary over the length of the array22.

This may be accomplished by the connection schemes shown in FIGS. 12 and13, wherein FIG. 12 shows up/down series connections 48 between thesolar cells 14 of the array 22, and FIG. 13 shows left/right seriesconnections 50 between the solar cells 14 of the array 22. In both FIGS.12 and 13, these series connections 48, 50 are electrical connectionsbetween the front contacts 32 and back contacts 34 of the solar cells14, and the bypass diodes 44, are made using the corner conductors 20formed on or in the exposed areas 28 of the substrate 12. These seriesconnections 48, 50 determine the current (power) flow, as indicated bythe arrows 52, through the solar cells 14, in contrast to the assemblyof large strings off-substrate.

The corner conductors 20 between solar cells 14 can be in many forms.They could be accomplished using wires that have electrical connectionsmade on both ends, which could be from soldering, welding, conductingadhesive, or other process. In addition to wires, metal foil connectors,similar to the interconnects could be applied. Metal conductive paths ortraces (not shown) can also be integrated with the substrate 12.

In summary, this new approach attaches the solar cells 14 individuallyto a substrate 12 such that the corner regions 26 of two, three or fouradjacent solar cells 14 are aligned on the substrate 12. The solar cells14 can be laid out so that the cropped corners 24 are aligned and thecorner regions 26 are adjacent, thereby exposing an area of thesubstrate 12. Electrical connections between solar cells 14 are made inthese corner regions 26 between front contacts 32 and back contacts 34on the solar cells 14, bypass diodes 44, and corner conductors 20 on orin the exposed area 28 of the substrate 12, wherein these conductivepaths are used to create a string of cells in a series connection 48, 50comprising a circuit.

Examples of the disclosure may be described in the context of a method54 of fabricating a solar cell, solar cell panel and/or satellite,comprising steps 56-68, as shown in FIG. 14, wherein the resultingsatellite 70 having a solar cell panel 10 a comprised of solar cells 14are shown in FIG. 15.

As illustrated in FIG. 14, during pre-production, exemplary method 54may include specification and design 56 of the solar cell 14, solar cellpanel 10 a and/or satellite 70, and material procurement 58 for same.During production, component and subassembly manufacturing 60 and systemintegration 62 of the solar cell 14, solar cell panel 10 a and/orsatellite 70 takes place, which include fabricating the solar cell 14,solar cell panel 10 a and/or satellite 70. Thereafter, the solar cell14, solar cell panel 10 a and/or satellite 70 may go throughcertification and delivery 64 in order to be placed in service 66. Thesolar cell 14, solar cell panel 10 a and/or satellite 70 may also bescheduled for maintenance and service 68 (which includes modification,reconfiguration, refurbishment, and so on), before being launched.

Each of the processes of method 54 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of solar cell, solar cell panel, satelliteor spacecraft manufacturers and major-system subcontractors; a thirdparty may include without limitation any number of venders,subcontractors, and suppliers; and an operator may be a satellitecompany, military entity, service organization, and so on.

As shown in FIG. 15, a satellite 70 fabricated by exemplary method 54may include a body 74, solar cell panels 10 a comprised of solar cells14, and antenna 76. Examples of the systems 72 included with thesatellite 70 include, but are not limited to, one or more of apropulsion system 78, an electrical system 80, a communications system82, and a power system 84. Any number of other systems also may beincluded.

FIG. 16 is an illustration of the solar cell panel 10 a in the form of afunctional block diagram, according to one example. The solar cell panel10 a is comprised of the solar cell array 22, which is comprised of oneor more of the solar cells 14 individually attached to the substrate 12.Each of the solar cells 14 absorbs light 86 from a light source 88 andgenerates an electrical output 90 in response thereto.

At least one of the solar cells 14 has at least one cropped corner 24that defines a corner region 26, such that an area 28 of the substrate12 remains exposed when the solar cell 14 is attached to the substrate12. When a plurality of solar cells 14 are attached to the substrate 12,the corner regions 26 of adjacent ones of the solar cells 14 arealigned, thereby exposing the area 28 of the substrate 12.

The area 28 of the substrate 12 that remains exposed includes one ormore corner conductors 20 attached to, printed on, or integrated withthe substrate 12, and one or more electrical connections between thesolar cells 14 and the corner conductors 20 are made in a corner region26 resulting from the cropped corner 24 of the at least one of the solarcells 14.

The corner region 26 resulting from the cropped corner 24 includes atleast one contact, for example, a front contact 32 on a front side ofthe solar cell 14 and/or a back contact 34 on a back side of the solarcell 14, for making the electrical connections between the cornerconductors 20 and the solar cell 14. The electrical connections maycomprise up/down or left/right series connections that determine a flowof power through the solar cells 14, and may include one or more bypassdiodes 44.

The description of the examples set forth above has been presented forpurposes of illustration and description, and is not intended to beexhaustive or limited to the examples described. Many alternatives,modifications and variations may be used in place of the specificelements described above.

To facilitate the electrical connections, it can be advantageous to havecorner conductors 20 fabricated onto or within the substrate 12 beforethe solar cells 14 are attached. This would be somewhat similar to a PCBwhere thin metal traces are present. In addition, multiple currentpathways can be built into the corner conductors 20. Moreover, one ormore conductive jumpers (not shown) may be added to the cornerconductors 20 to determine which pathways are used. Alternatively, oneor more conductive pathways may be removed from the corner regions tofacilitate the determination of the current pathways between solar cells14.

Preferably, the substrate 12 includes conductive paths throughout,including conductive paths on its surface (e.g., the corner conductors20), beneath its surface and beneath the plane of the solar cells 14(not shown), or both on its surface and beneath its surface. Theconductive paths, such as the corner conductors 20, are electricallyinsulated from the solar cells 14. In addition, the corner conductors 20provide access to one or more of other conductive paths of the substrate12. As a result, this design would virtually eliminate any manual wiringon the panel 10 a.

It is desirable to have the greatest area possible on the panel 10 adedicated to the solar cells 14 and have small corner regions. However,a desire to provide all possible permutations of cell-to-cellconnections in the corner regions will motivate for large cornerregions. Balancing these competing interest will depend on the design.

Competition between interests can be avoided by using the power routingmodule (PRM) 30. The PRM 30 can embody some or all of the cornerconductors 20 between the solar cells 14 and can be applied to thecorner region. Different versions of the PRM 30 facilitate purpose-madewiring. Moreover, the PRM 30 can shrink the size of the corner region26, while providing for the needed variation in conducting pathways, ascompared to having the conductive paths on the substrate 12.

Printing corner conductors 20 directly into the corner region 26 isanother approach to make purpose-made wiring. This requires lessconducting pathway options and can be smaller.

Another variation is the possibility of adding a multiplexing switchmodule (not shown) into the corner regions 26. The multiplexing switchmodule could be integrated into the substrate 12 or the PRM 30. Themultiplexing switch module would be programmed to make the desiredelectrical pathways between the solar cells 14 and the corner conductors20.

For example, the multiplexing switch module could be programmed once and“burned in,” or could be addressable and altered during operation. Whenburned-in, the multiplexing switch module may be programmed through atemporary external connection. There may also be additional conductorsin the substrate 12 that address and program the operation of all of themultiplexing switch modules that may be installed across the panel 10 a.In addition, a multiplexing switch module that can be addressed andoperate while in orbit will have great advantages.

The assembly of the solar cells 14 in arrays in this manner will greatlysimplify manufacturing and enable automation while preserving theability for customization. The key is that the electrical connectionsbetween adjacent solar cells 14 is completed on the substrate 12 usingthe corner conductors 20. Thus, the panel 10 a layout and manufacturingof the layout is independent of the final design and can be common forvirtually any design.

1. A solar cell panel, comprising: a solar cell array comprised of oneor more solar cells and a substrate for the solar cells, wherein: anarea of the substrate remains exposed when at least one of the solarcells having at least one cropped corner is attached to the substrate;the area of the substrate that remains exposed includes one or morecorner conductors; and one or more electrical connections between thesolar cells and the corner conductors are made in a corner regionresulting from the cropped corner of the at least one of the solarcells.
 2. The solar cell panel of claim 1, wherein the at least onesolar cell comprises a plurality of solar cells attached to a substratesuch that corner regions of adjacent ones of the solar cells arealigned, thereby exposing an area of the substrate, and the electricalconnections between the solar cells are made in the exposed area of thesubstrate using the corner conductors formed on or in the exposed areaof the substrate.
 3. The solar cell panel of claim 1, wherein the solarcells are individually attached to the substrate.
 4. The solar cellpanel of claim 1, wherein the solar cells are attached to the substrateas cell, interconnect and coverglass (CIC) units.
 5. The solar cellpanel of claim 1, wherein the corner conductors are attached to, printedon, or integrated with the substrate before the solar cells areattached.
 6. The solar cell panel of claim 1, wherein the substrateincludes conductive paths on its surface, beneath its surface, or bothon its surface and beneath its surface.
 7. The solar cell panel of claim6, wherein the conductive paths are electrically insulated from thesolar cells.
 8. The solar cell panel of claim 1, wherein at least one ofthe electrical connections between at least one of the solar cells andat least one of the corner conductors is made after the at least one ofthe solar cells has been attached to the substrate.
 9. A method forfabricating a solar cell panel, comprising: fabricating a solar cellarray comprised of one or more solar cells and a substrate for the solarcells, wherein: an area of the substrate remains exposed when at leastone of the solar cells having at least one cropped corner is attached tothe substrate; the area of the substrate that remains exposed includesone or more corner conductors; and one or more electrical connectionsbetween the solar cells and the corner conductors are made in a cornerregion resulting from the cropped corner of the at least one of thesolar cells. 10-16. (canceled)
 17. A device, comprising: at least onesolar cell, wherein the solar cell has at least one cropped corner thatdefines a corner region, such that the corner region resulting from thecropped corner includes at least one contact for making an electricalconnection to the solar cell.
 18. The device of claim 17, wherein thecontact comprises a front contact on a front side of the solar cell. 19.The device of claim 17, wherein the contact comprises a back contact ona back side of the solar cell.
 20. The device of claim 17, wherein thecontact extends into the corner region.
 21. The device of claim 17,wherein the at least one solar cell comprises a plurality of solar cellsattached to a substrate such that corner regions of adjacent ones of thesolar cells are aligned, thereby exposing an area of the substrate, andelectrical connections between the solar cells are made in the exposedarea of the substrate using corner conductors formed on or in theexposed area of the substrate.
 22. The device of claim 21, wherein theelectrical connections are series connections that determine a flow ofpower through the solar cells.
 23. The device of claim 22, wherein theseries connections are up/down series connections.
 24. The device ofclaim 22, wherein the series connections are left/right seriesconnections.
 25. The device of claim 21, wherein one or more bypassdiodes are added to the exposed area of the substrate for use in one ormore of the electrical connections.
 26. The device of claim 17, whereina bypass diode is applied to a back side of the cell, with aninterconnect or contact for the bypass diode extending into the cornerregion.
 27. A method, comprising: fabricating at least one solar cell,wherein the solar cell has at least one cropped corner that defines acorner region, such that the corner region resulting from the croppedcorner includes at least one contact for making an electrical connectionto the solar cell. 28-36. (canceled)